For the practise of this sport, it is necessary that the shoe of the user should be held securely to the board in a given position, and with a given orientation that corresponds to the point of balance sought for optimal skiing. This is achieved, in a manner with which one is familiar, by the employment, for each shoe, of an intermediate securing device that is mounted on the board at a given position but with an orientation that can be adjusted, with said device acting as a receptacle for the shoe and possessing means that are used to lock the latter in position when it is positioned in said device.
For example, a disk is placed at the given position on the board, and at its base, the securing device includes a circular aperture into which the disk of the ski-board can be registered at an angular position which is determined in relation to the general direction of the board. One thus achieves a connection between the base and the board, the angle of which can be adjusted.
Document FR.2.751.238 describes a securing device to be mounted on a ski-board, for the attachment of a shoe to said board that includes a shell whose base is extended at the sides by lateral edges. This device includes two straps, intended respectively to hold the instep in one case and the forefoot at the toes in the other. Each strap is connected, by one of its two ends, to the lateral edge of the base, while the two other ends of the two straps are connected together by a connecting bar designed to mate with additional locking means placed in a fixed manner on the other lateral edge of the base. The use of this single connecting bar allows simultaneous tensioning of the two straps on the shoe by the use of a single locking action.
In one embodiment, the lateral edge includes a fixed pin on the outside, and the connecting bar is terminated at the front by an open fork designed to fit onto the fixed pin, which then constitutes a hinged bearing point for the connecting bar, in the manner of a lever for tensioning the straps until such time as another attaching element, formed toward the rear of the connecting bar, mates with a complementary latch mounted at the rear of the lateral edge, which can consist of notches created on the outer surface of the connecting bar, designed to mate with notches formed on a hinged locking element at the rear of the lateral edge. Thus, for the locking of a shoe in the securing device, the user must move the connecting bar from back to front so as to engage the fixed pin in the fork, and must then pivot the rear of the connecting bar about said pin until such time as the notches created on the outer surface of the connecting bar engage in the notches formed on the inner face of the latch. Said latch is fitted with elastic return means, so as to allow automatic locking of the connecting bar.
In a second embodiment, the connecting bar takes the form of a rod of circular section. Toward the front, the lateral edge of the base includes a blind hole that is calibrated to serve as a receptacle at the front end of the connecting bar and, toward the rear, an attachment device configured to serve as a means for fixing to the rear end of the connecting bar. The tensioning of the straps is achieved by virtue of an elbowed part, in the shape of a crank, on the connecting bar between its front and rear ends, with this tensioning being effected, after engagement of the front end in the through hole, and the rear end on the attachment device, by tilting the crank downwards.
In these two embodiments, each of the two straps is composed of two parts connected together by means for locking and adjusting the length. More precisely, the part that is immediately adjacent to the connecting bar is a piece of serrated strap, with its locking system.
Although it can be used to effect the locking of the two straps during a given operation that is suitable to be performed with one hand by the user, the embodiments recommended in document FR.2.751.238 is not fully satisfactory. In particular, the preliminary positioning of the front end of the connecting bar requires a high degree of accuracy and therefore concentration by the user, whether for fixing the fork onto the fixed pin of the lateral edge in the first example, or introduction of the front end of the rod into the through hole in the second example. In particular, there exists a significant risk of involuntary operation of the means for locking the rear of the connecting bar, due to the fact that they are located at the lateral edge and also on the outside of the shoe.